Radio signaling system and apparatus



RADIO SIGNALING SYSTEM AND APPARATUS Filed Sept. 20, 1933 2 Sheets-Sheet 1 RE AM PL.

\L RF AHPL. 3 DET I 76.

AEAMPL. 7 75 H" 56 INVENTOR.

Howard J find/8y.

ATTORNEY.

April 1937- I H. J. FINDLEY 2,077,552

RADIO SIGNALING SYSTEM AND APPARATUS Filed Sept. 20 1933 2 Sheets-Sheet 2 (19 I I I 6 a2 dcbh 3 i I INVENTOR.

Howard. J find/e}.

BY @WZMW ATTORNEY.

Patented Apr. 20, 1937 UNITED STATES PATENT OFFICE Howard J. Findley, Cleveland, Ohio, minor to The Bishop & Babcock Mfg. Company, Cleveland, Ohio, a corporation of Ohio Application September 2., 1933, Serial No. 690,243

11 Claims.

This invention relates to signaling systems and apparatus and particularly to signaling systems and apparatus for vehicles such as automotive vehicles.

Certain aspects of my invention may be practiced with particular advantage in connection with a vehicle equipped with a radio receiver or so-called receiving set by which broadcasted signals, programs etc. may be received by the vehicle driver and passengers of the vehicle; but as will appear hereinafter, certain particular advantages of my invention may be enjoyed entirely apart from such radio reception.

It is an object of my invention to provide generally an improved signaling system and apparatus.

Another object is to provide a signaling system and apparatus employing the principles of radio reception and amplification in an improved manner.

Another object is to provide a signaling system and apparatus whereby electrical oscillations may be produced at will of predetermined frequency in an electric circuit and translated into amplified sound signals of predetermined musical tone irequency, in an improved manner.

Another object is to provide a signaling system and apparatus whereby electric oscillations may be produced at will in an electric circuit at any one of a plurality of frequencies selectively, singly or in sequence, and translated into amplified sound-signals -of corresponding predetermined musical tone frequencies in an improved manner.

Another object is to provide, in a signaling system and apparatus in which oscillations in an electric circuit are translated into amplified sound. signals, improved control means ior selectively varying the frequency of the oscillations to eflfect the production of signals of selectively ditl'erent tone pitch.

Another object is to provide, in a signaling system and apparatus in which oscillations in an electric circuit are translated into amplified sound signals of predetermined musical tone frequency, improved control means to selectively vary the frequency of the oscillations to efiect the production of signals of a plurality of different musi tem and apparatus of the class whereby a plurality of different kinds of audible signals may be produced electrically, improved control means for eiiecting selection and production of the signals.

Other objects will be apparent to those skilled in the art to which my invention appertains.

My invention is fully disclosed in the following description taken in connection with the ac companying drawings, in which:

Fig. l is a diagrammatic representation of electric circuits and apparatus whereby my invention may be practiced in One form;

Fig. 2 is a view illustrating a form of control apparatus which may be employed with the circuits of Fig. 1 and which is illustrated diagrammatically in Fig. 1;

Fig. 3. is a sectional view taken from the plane 3-4 of Fig. 2;

Fig. 4 is a view generally similar to Fig. 1 but illustrating a modification which I may employ;

Fig. 5 is a view similar to Fig. 2 but illustrating a controller which may be utilized with the modification of Fig. 4;

Fig. 6 is a sectional view taken from the plane 8-6 of Fig. 5;

Fig. '7 is a fragmentary sectional view taken from the plane 1-1 of Fig. 6;

Fig. 8 is a fragmentary sectional view taken from the plane 8-8 of Fig. 3.

Referring to the drawings, Fig. 1, I have shown at I a three-element electron tube, which may be of well known construction as commonly employed in radio apparatus. At 2 and 3 are condensers of selected capacitance. At 4 is an iron core transformer, and at 5 a rheostat or resistance unit associated with which is a plurality, such as eight, manually operable switches 6--i by which the resistance of the rheostat 5 in the circuit to be described may be selectively varied.

The apparatus thus far referred to and suitable electric circuits which will be described constitute what may be called an oscillator inasmuch as electric oscillations may be set up therein, the irequency of which may be selectively varied by the switches 6-4.

At l is a manually operable switch having a knob or handle 8 and comprising a shaft 9 rotatable by the handle, and arms l0, H and i2 projecting radially from the shaft 9 engageable selectively with three corresponding groups of three contacts each indicated by the reference characters I: to 2| inclusive.

At 22 is a sound amplifying horn or loud speaker of the dynamic type having an armature winding 23 and a field winding 24. The horn 22-23-24 may be of any known or suitable construction whereby current impulses transmitted to the armature winding 23 may react upon the magnetism generated by the field winding 24 and translate the current impulses into sound waves amplified by the horn 22.

The other elements of apparatus illustrated in the figure and employed in the preferred practice of my invention may be those well known in the art and will be described or identified in the following description of the mode of operation thereof.

According to this preferred mode of operation, the operator of the apparatus, for example the driver of a vehicle on which the apparatus is installed, may cause the horn 22 to emit musical tones as signals. Tones of any one of a plurality of different pitches such as eight different tones may be sounded, or these tones may be sounded in sequence having the character of musical tunes. The switch knob 3 may normally rest in the hom" position indicated in Fig. 1 or may be upon occasion moved to that position whereupon the switch arms 10, II and I2 will respectively move into engagement with the contacts I4, I1 and 20. This will energize the filament 25 of the oscillator tube I along the fol lowing circuit, from ground 23 through battery A and by wires 21, 23, arm I2, contact 20, wire 29 to the filament and thence to ground. Current may also flow from the battery A and by wires 21 and 28, arm I2, contact 20 and wire 30 to the horn field winding 24 and thence by wire 3| back to the battery A, energizing the horn field. A high potential is established between the filament 25 and the tube plate 32 by a battery B, the circuit being traced from ground 33 to the filament 25, thence to the plate 32 and by wires 35 to the primary 34 of the transformer 4, and thence by wire 33 to the upper part of the battery B and thence to ground.

A local oscillation circuit is provided comprising the condenser 3, the transformer secondary 31, a wire 39, the resistance 5, through one or the other of the switches 3, and a wire 43, one side of this circuit being connected to the ground 33 and the other by a wire 4| to the tube grid 33.

Oscillations are set up in this circuit upon closing any one of the switches 33 due to the fact that the current in the plate circuit above described comprising the transformer primary 34 reacts upon the oscillating circuit through the secondary 31 of the transformer and the current in the oscillating circuit in turn reacts upon the plate circuit through the grid 33.

The frequency of oscillations in this circuit will be determined by the well known factors of resistance, capacitance and inductance of the circuit, and the elements of the resistance 5 are so proportioned that upon closing any one of the switches 3, the circuit will oscillate and oscillate at a musical tone frequency. Preferably the different frequencies thus effected will have the relative interval relation of the eight tones of a diatonic musical scale one octave in extent.

The oscillations thus produced are amplified in a two-tube amplifier, the three-element electron tubes of which are illustrated at 42 and 43. These tubes have plates 44 and 45, grids 43 and 41 and filaments 43 and 49. The filaments are energized by the battery A across the wires 3| and 21 above described. A plate circuit is energized by the battery B and the circuits therefor may be traced from the wire 3|, to filament 43 and thence to the plate 44 and transformer primary 50 to a positive connection on the battery B and through the battery to negative. A similar circuit is provided for the plate 45 through a transformer primary 5| and by a wire 52 to a higher point on the battery B and thence to negative at the other end of the battery B.

The oscillations in the oscillator circuit are impressed upon the grid 43 of the tube 42 by a circuit which may be traced from the plate 32 of the tube through the condenser 2 and by a wire 53 to contact |4, arm l0, and a wire 54 to the grid 43, the polarity of the plate 32 differing from that of the filament 43 and responding to voltage fluctuation effected by the oscillations.

The oscillations in the grid 43 are amplified in the circuit of the plate 44 in the well known manner and induce corresponding oscillations in the transformer secondary 55 and correspondingly in the circuit of the grid 41. the plate 45 and primary 5| again amplify the oscillations and they are correspondingly induced in the transformer secondary 53.

It will be seen that the amplifying circuits of the filament, grid and plate of the tubes 42 and 43 are those of the well known audio frequency amplification of a broadcast radio receiving set except that the grid 43 of the first tube responds to the oscillations in the wire 54 instead of from the usual transformer secondary 51. ondary 51 is illustrated in the drawings for a purpose to be described but does not function as a secondary of a transformer in the system being considered at this point.

The oscillations produced as above described and now greatly amplified in the'transformer secondary 53, are impressed upon the armature winding 23 of the horn 22 by a circuit including the wires 33, 3|, armature winding 23, wire 32, switch contact l1, arm II, and wire 33, and are converted into sound of great magnitude in the horn 22 in the well known manner above referred to. And inasmuch as the sounds are produced from amplified oscillations of musical tone frequency, the horn will emit musical tones. As will now be clear, the musical tones emitted by the horn may be varied by closing selectively one or another of the switches 33 to vary the periodicity of the oscillations. Likewise, the signal emitted by the horn may be made to be in the nature of a musical tune by closing the switches one after another in the suitable sequence.

Thus signals of great variety as well as of great beauty maybe produced by the horn 22.

By means of a very small addition to the system above described, the horn 22 may be made to emit voice signals amplified so as to be distinctly heard outside of the vehicle by the drivers of other vehicles or by persons generally. For this purpose, a transmitter 35 is provided disposed at a convenient place in the vehicle and connected by a wire 33 to ground and by a wire 31 to the contact point l3.

The transmitter 35 is of the type which will convert voice vibrations into electric current impulses. When it is desired to effect this type of signal, the switch 3 is rotated to the "talk" position. This cuts out the oscillator circuit wire 53 so that the horn 22 will no longer be responsive to musical tone signals and eifects the circuit for the transmitter impulses, from the contact l3 above mentioned to arm I0, wire 54, whereby the impulses are impressed upon the grid 43 of the tube 42. It will be observed that although the switch arms H and I2 are moved over from con- The circuit of This sectact points l1 and 28 to II and II respectively, the circuits thereof are not changed so that now the voice impulses transmitted over the wire 54 will be amplified and converted into amplified sound by the horn 22.

The amplifying apparatus and circuit comprising the tubes 42 and 48 and the transformers 5055 and 5l--56 may be of a type commonly employed as an audio frequency amplifier to amplify signals, program and the like commonly broadcasted from boardcasting stations. Therefore, when such an amplifying circuit is employed for the signaling means above described in connection with the horn 22, such amplifying circuit may conveniently be employed for the reception of broadcasted programs by the addition of a radio frequency amplifying circuit and apparatus. This is indicated in Fi 1.

At 68 is indicated diagrammatically a panel behind which and not shown may be provided the usual or an Su table radio frequency amplifying and detector apparatus and circuit, adapted to be energized from an antenna 69 associated with the ground 18 and having a transformer primary II which may be associated with the above described transformer secondary winding 61.

A tuning dial 12 and a control switch I3 of usual or any suitable construction may be provided to close the circuit or circuits of the radio frequencyampliflcation and to tune the same and the detector circuit to incoming signals and to adjust the volume thereof in a well known manner.

Such signals will be transmitted through the transformer I I -5'l to the audio amplification circuit and apparatus above described; and such incoming signals or broadcast programs will be delivered to the circuit of the transformer secondary 56. When such signals are received by broadcast, the switch handle 8 may be turned to the radio position whereby the amplified current impulses in the secondary 66 may flow over a circuit including the secondary itself, the wire 63, am ll, contact l8, a wire 14, through the armature winding 15 and by wire 68 back to the secondary of the transformer. The armature winding 16 may be that of a dynamic loud speaker having a field winding 16 and a soundamplifying horn or the like 11. The field '16 may have an energizing circuit, closed upon operation of the switch to the radio position, as follows, from positive ofthe battery A by wire 21, arm II to contact 2|, and thence by wire 18 to the field winding 16 and thence by wire 8! to the A battery negative.

Incoming programs will thus be amplified and given out on the horn 11 which may be located within the vehicle for the entertainment of passengers therein. At such time, as will be observed, the switch 8 throws out of the circuit the amplifying horn 22 and the oscillating circuit and circuit of the transmitter 66.

In Figs. 2, 3 and 8 is illustrated one form of a controller means for operating the signal system and apparatus of Figs. 1 and 2 and embodying switches 6-6, the switch I, and, where it is desired also to receive broadcasted programs, em-

bodying a switch 13 and a tuning dial I2.

suitable bore in the housing cover 6!.

The controller comprises a housing 86 having a cover 8|. The switches indicated generally at 6 are preferably of the push button type comprising a push button element 82 reciprocable in a A resilient switch finger 83 is engaged by the button and upon depressing the button is bent downwardly to engage another resilent switch finger 84 to close an electric and to perform the circuit functions of the switch 6 of Fig. 1. Suitable circuit connections may be made to the fingers 83 and 84 corresponding to those of Fig. l but not shown in Figs. 2 and 3.

The several switches 6 may be disposed in a line as shown in Fig. 2 convenient to the fingers and thumb of the vehicle driver. To this end, the housing in general may be secured to the steering column of the vehicle as shown generally at 88.

The switch I of Fig. 1, illustrated generally at I in Figs. 2 and 3, comprises a shaft 85 of insulating material rotatably mounted in suitable bearings 88 and 89 in the housing and housing cover, respectively, and may be rotated or oscillated by a knob 8 externally of the cover. Three switch arms I8, II and I2, secured to corresponding heads 86-86--86 are rigidly secured to the shaft 85 by set screws 9! in the heads 86. Three shelves 81 of insulating material carry each three contacts in an arc about the axis of the shaft 85 as shown in Fig. 8 for the switch arm II. A circuit wire is soldered to each of the heads 86 and wires are connected to each of the contacts on the shelves 81, see Fig. 8, and by the construction thus described it will be apparent that the circuit wires of Fig. 1 brought to the diagrammatic switch I of that figure may be brought to the switch 1 of Figs. 2, 3 and 8 and controlled by the operation of the switch knob 8 as and for the purposes set forth in connection with Fig. 1.

The controller cover 8| may have position points 92, 93 and 94 cooperating with a single point 85 on the switch knob 8 to indicate externally the positions of the switch arms I, l l and I2 and legends such as talk, horn", "radio, may be associated with the switch points as more fully described in connection with Fig. 1.

The switch 13 may, as in common practice of the radio frequency amplifying circuits and apparatus, have an off" position and a plurality of volume control positions as clearly indicated in Fig. 2.

In this connection it may be stated that whereas in Fig. 2 circuits from the batteries A and B, such for example as the filament circuits, are illustrated as constantly closed, this has been done to simplify the drawings but it will be understood that, as in common practice in circuits of this general class, the circuits may be controlled by switches such as i58-l5l in a well known manner; and if desired, such switch contacts can be under the control of the switch 13 to be opened when it is in its off position.

Where the radio frequency amplifying circuit and apparatus are not employed for the reception of incoming programs, the control of the A and B battery circuits may be effected in any suitable manner which will be clearly understood by those skilled in this art, to effect opening of these circuits when the system and apparatus are not in use.

When it is desired to signal by means of the human voice, the driver will move the switch I to the talk position and thereby can communicate through the horn 22 vocally with people generally outside of his car. Occasionally the switch I may be moved to the radio" position to receive incoming broadcasted programs, particularly at times when the vehicle is parked or on the open road where there is little probability that the talk or horn signals may be needed.

It will thus be apparent that my invention may be practiced without the radio frequency amplifying circuits and apparatus but inasmuch as the signaling system and apparatus proper,

including the oscillating circuit and the transmitter 65 and the horn 22, utilizes an amplifying circuit and apparatus comprising the tubes 42 and 43 suitable for amplifying broadcasted programs, the latter may be enjoyed by the addition only of the radio frequency amplifying circuits and apparatus supplemental thereto, and at slight additional expense and complication.

In Fig. 4 I have illustrated a modification of the circuit of Fig. 1, and in Figs. 5 and 6 a corresponding modification of controller means therefor. In this form, a switch I00 is provided corresponding to the switch I of Fig. 1 but controlling only the talk and the radio functions thereof, and a switch I M is provided having a convenient mode of operation whereby by a single movement on the part of the driver, the talk and radio" functions of the system and apparatus may be cut'ofi or stopped and the horn" 35 function initiated.

If the switch I00 is in, say, the radio position to receive broadcasted programs, the secondary 66 of the transformer of the audio frequency amplifier which is energized by the received programs, will have a circuit by a wire I02 through a bar I03 of the switch IOI normally engaging suitable contacts at its opposite ends as illustrated, and thence by wire I04 to switch arm II, contact I05 and wire I06 to the armature 45 winding I5 of the horn I1, and by wire 16' to the transformer 56.

The field winding 16 for the horn l'l will be energized from the A battery forming part of the audio frequency amplifying circuit and apparatus 50 indicated generally at I01 and comprising apparatus and circuits fully described in connection with Fig. 1, and the circuit may be traced from wire 3| leading to one side of the battery as will be understood, through the field winding 16, by wire 55 I06 to the contact I00 and thence by switch arm I2 and by wire IIO back to the other side of the A battery.

Thus, upon moving the switch knob 3 to the radio position, programs may be received in the 60 vehicle from the horn 11.

Again, if the knob 6 be turned to the talk position, the horn 22 may be utilized to amplify voice signals originating in the vehicle. The transmitter 66 will cause current to flow along the circuit 66666I through a switch bar I I I engaging contacts at its opposite ends, and by wire H2 and contact I I3 to the switch arm I0, and thence to wire 64 whereby the impulses will be impressed upon the audio frequency amplifying circuit as described in connection with Fig. 1. At the same time, the armature winding 23 of the horn 22 will be energized along a circuit from transformer 66 by wire I02, switch bar I03, wire I04, switch arm 75 II, contact I I 2, wire II3, to the armature winding 23 and thence by wire ii to the transformer secondary 66. At the same time, the field 24 is energized from the A battery above referred to by wire 3| through the field winding 24 by wire H4, contact H5, switch arm I2 and wire H0 back to the other side of the A battery.

Thus upon turning the switch knob to the talk" position, the reception of broadcast programs will be interrupted on the horn ll and vocalvoice signals may be emitted from the horn 22. For this purpose, and also for the corresponding purposes of Fig. 1, the transmitter 66 may be provided with extension wires 66 and 61 whereby it may be conveniently moved to the speaker's mouth, and when not in use may be disposed at any convenient point within reach.

Whether the switch knob 8 be in the talk" or the radio position above referred to, if at any time the driver wishes to signal with musical tones from the horn 22, he may do this by operating the switch IM and one or another of the switches 6-6. In operating the switch IOI as viewed in Fig. 4, a large push button II6 is depressed and the bars I03 and III thereof as well as bars Ill and I I0 thereof are depressed to their dotted line positions illustrated. The bar I03 breaks the circult therethrough above described and makes a circuit through suitable contacts from the wire I02 to a wire H6. The bar I" makes a circuit from wire I20 to wire I2I. The bar III breaks the above described circuit therethrough and makes a circuit from wire I 22 to wire I23, and the bar II6 makes a new circuit from wire I24 to wire I26.

As was described in connection with Fig. 1, a filament circuit for the oscillator tube IOI forming part of the oscillator" apparatus I26 of Fig.

4 is made to the positive side of the battery A along a circuit including the wire 20, wire I20, contact bar Ill, wire I2I, wires I26 and I I0 to the battery. The oscillating circuit I26, upon oscillating, impresses the oscillations, by way of wire 63, wire I22, contact bar III, wire I23 and wire 64 upon the audio frequency amplifying circuit and apparatus as before. The armature winding 23 is energized from the transformer 66, by wire I02. through contact bar I03 and by wires I I0 and H3, through the armature winding and by wire 6| back to the transformer. The field winding 24 is energized over a circuit including the wire 3i from the A battery, through the field winding 24,

by wire I26, contact bar 0, wires I26 and 0 back to the A battery.

It will thus be seen that whether the knob 3 is in either the talk" or the radio" position or in a neutral position therebetween, upon pressing the switch button II6, the circuits will automatically thereby be changed to cut out the talk" or radio"circuits and start the oscillating circuit and energize the field and armature of the horn 22 and cause it to emit a musical tone depending upon which switch 6-6 is closed. By means of a spring I2'I, the switch button II6 will be retracted upon removing the operator's hand therefrom to rethe housing I30 and cover I3I, has switch arms I II and I 2 mounted thereon cooperating with contacts upon insulated shelves I33-I33. The construction of switch 8-432 and of the arms I0, II 6 and I2 and the contacts on the shelves I33 may be similar to or identical with the corresponding parts including the shaft 85 and arms I0, II and I2 and shelves 81 of Figs. 2 and 3, except that the shelf is provided only with two contacts, such as the contacts I I5 and I09 or I I2 and I05 of Fig. 4, instead of the three contacts of the other form.

The push button H6 and the bars I03, III, III and I I8 of Fig. 4 are reproduced in Fig. 6 mounted upon a longitudinally reciprocable shaft I34 and the bars are adapted to normally engage and connect corresponding pairs of resilient fingers I35I35. A spring I21 reacting at one end upon a portion of the cover I3I and at the other end upon a shank I36 of the button II6 normally holds the shaft I34 in an outer position in which pairs of resilient fingers I35 are connected by the bars I03 and I I l. Upon depressing the button II6 to move the shaft I34 inwardly, the bars I03, III, III and H8 all engage pairs of resilient fingers I35. The bars of Fig. 6 correspond to those of Fig. 1 and the resilient fingers I35 correspond to the pairs of small circular contacts such as I3'I in Fig. 1, and it is therefore believed unnecessary herein to complicate the description by a further elaboration of the electrical connections made by reciprocatory movements of the switch button H6. The resilient fingers I may all be mounted upon an insulating support I38 secured to the housing I30, and, as will now be understood, upon depressing or releasing the button II6, circuits will be established in a diagram such as that of Fig. 4 corresponding to the circuit connections effected by depressing or releasing the button II6 of Fig. 4.

0 The switches 6-45 of Fig. 4 are, in the form of Figs. 5 and 6, of push button type comprising a plurality of push buttons I39-I39 each having a shank I40 slidable in a suitable bore in the cover I3I of the housing, and inwardly of the housing adapted when depressed to bend a resilient switch finger I4I downwardly to engage a corresponding stationary resilient finger I42. The operation of each button in this respect may close an electric circuit such as that closable by the switches 6 of Fig. 4.

It is believed that the operation of the controller of Figs. 5 and 6 in connection with the circuit of Fig. 4 will now be clear in view of the more complete description hereinbei'ore of the first described form.

In operation, with the button H6 in its outer position, the switch knob 8 may be turned either to the talk or the radio positions illustrated in Fig. 5 and will effect the circuit connections described in connection with Fig. 4, either to rece ive broadcasted programs or to, efiect signals of amplified voice. In any position of the knob 9, if the operator desires to effect musical tone signals, he may first depress the button I I6 as for example by the heel or palm of his hand, and with the fingers and thumb of his hand may depress one or another of the push buttons I39, each button corresponding to a dififerent musical tone or signal. The push buttons I39 are preferably disposed in a circular are around the push button IIB as a center to more conveniently dispose them under the fingers and thumb of the operators hand.

Thus, it will be seen that with the form of 75 Figs. 4, 5 and 6, the apparatus is always in condition for the immediate emission of loud musical tone signals without regard to the "talk or "radio functions, these latter being automatically eliminated upon pressing the button IIIS.

If preferred, the buttons I39 may be constructed so that any one of them may be depressed and retained in depressed position. This construction may comprise a pin I44 through the 'shank I40 of the button, slidable in a lateral groove I45 in a boss I46 in which the shank of the button slides. Upon depressing the button and engaging the contact fingers MI and I42, the button may manually be rotated to bring the pin I45 under the face of the boss as illustrated in Fig. 7 where the pin is shown in the position I41, and upon releasing it the button will be retained depressed.

Thereafter, by merely depressing the button I I6, the signal in this manner preselected, will be sounded. This provision makes possible a more immediate signal since only the button IIB needs to be operated to effect such signal.

Where the push buttons I39 are all left in their open circuit position, it will be apparent that after the push button II6 has been depressed, they may be operated in sequence to effect the emission of signals having the character of a musical tone.

I claim:

1. In a signal system for motor vehicles and the like, in combination with a passenger compartment of the vehicle having a compartment wall, a first electrically energizable sound-producing device disposed on one side of the wall in the passenger compartment in a position to be more readily audible internally than externally of the passenger compartment, a second electrically energizable sound-producing device disposed on the vehicle on the other side of the wall in a position to be more readily audible externally of the passenger compartment than internally thereof, an electronic tube type radio receiver, and electronic tube type oscillator, an electronic tube type amplifier, and a manually operable two-position switch all mounted on the vehicle, and with the switch within reach of a vehicle occupant, means causing the two-position switch to normally take up a first position and in that position closing by its contacts, circuit means effecting energization of the first sound-producing device by the radio receiver through the amplifier, and operable to the second position to open said closed contacts same amplifier.

2. In a signaling system for motor vehicles and the like, in combination with a passenger compartment of the vehicle having a compartment wall, a first electrically energizable sound-producing device disposed on one side of the wall in the passenger compartment in a position to be more readily audible internally than externally of the passenger compartment, a second electrically energizable sound-producing device disposed on the vehicle on the other side of the wall in a position to be more readily audible externally of the passenger compartment than internally thereof an electronic tube type radio receiver, an electronic tube type oscillator, an electronic tube type amplifier and a manually operable two-position switch all mounted on the vehicle and with the switch within reach of a vehicle occupant, the

switch adapted, in a first position, closing by its contacts, circuit means eifecting energization of the first sound-producing device by the radio receiver through the amplifier, and operable to the second position to open said closed contacts to effect interruption of said energization oi the first sound-producing device and in said second position closing, by other contacts, circuit means to eiIect energization of the second sound-produc- 10 ing device from the oscillator through the same amplifier. I

3. A signaling system and apparatus as described in claim 1 and in which the means causing said two-position switch to take up said first position is resilient means and after operation to the second position the resilient means may automatically return the switch to said first position.

4. A signaling system and apparatus as described in claim 1 and in which the said two-position switch is of the push button type and when in said first position the push button thereof is elevated and the switch is operable to said second position by depression of the button.

5. A signaling system as described in claim 1 and in which the oscillator is provided with a plurality of switches operable selectively, singly or in a group to change the periodicity of the oscillations produced by the oscillator.

6. A signaling system and apparatus as described in claim 1 and in which the oscillator is provided with a plurality of switches operable selectively, singly or in a group to correspondingly change the periodicity of the oscillations 35 produced by the oscillator and means is provided to cause the said switches to be optionally automatically retained in operated position after being operated.

7. A system and apparatus as described in claim 1 and in which the said two-position switch is of the push button type and when in said first position the push button is elevated and the switch is operable to said second position by depressing the button, and in which the oscillator is provided with a plurality oi push button switches disposed in a series generally concentric with respect to the said two-position switch push button and operable selectively, singly or in a group to correspondingly change the periodicity of the oscillations produced by the oscillater.

8. A system and apparatus as described in claim 1 and in which the said two-position switch is of the push button type and when in said first position the push button is elevated and the switch is operable to said second position by depressing the button, and in which the oscillator is provided with a plurality of push button switches disposed in a series generally concentric with respect to the said two-position switch push button and operable selectively, singly or in a group to correspondingly change the periodicity of the oscillations produced by the oscillator, and means is provided to cause the said selected ones of the plurality of switches to be optionally retained in operated position after being operated.

9. In a signal system for motor vehicles and the like, in combination with a passenger compartment oi! the vehicle having a compartment wall, a first electrically energizable sound-producing device in the passenger compartment on one side of the compartment wall positioned to be more readily audible internally than externally of the passenger compartment, a second electrically energizable sound-producing device on the other side of the compartment wall disposed to be more readily audible externally than internally of the passenger compartment, an electronic tube type radio receiver, a source of sound wave produced current undulations, an electronic tube type amplifier, and a manually operable two-position switch mounted on the vehicle, and with the switch within reach of a vehicle occupant, means causing the two-position switch to normally take up a first position and in that position closing, by its contacts, circuit means eilecting energization of the first sound-producing device by the radio receiver through the amplifier, and operable to a second position to open said closed contacts to efiect interruption of said energization oi the first sound-producing device and in said second position closing, by other contacts. circuit means to effect energization of the second sound-producing device from the said current undulation source.

10. In a signaling system for motor vehicles and the like, an electrically energizable sound producing device, an electronic tube type oscillator, an electronic tube type amplifier, and an electric switch construction all adapted to be mounted on the vehicle with the switch convenient to the vehicle driver, the switch construction comprising a plurality oi switches operable collectively, singly or in a group to correspondingly change the periodicity of the oscillations produced by the oscillator and adapted to be optionally and automatically retained in operative position, switch means normally in a restored condition and operable to efifect energization of the sound producing device from the oscillator, a second sound producing device operable through the amplifier, and movement of the switch means energizing the first sound producing device being adapted to de-energize the second sound producing device.

11. In a signaling system for motor vehicles and the like, an electrically energizable sound producing device, an electronic'tube type oscillator, an electronic tube type amplifier, and an electric switch construction all adapted to be mounted on the vehicle with the switch convenient to the vehicle driver, the switch construction comprising a first switch of the push-button type normally restrained in restored position with the push-button elevated and operable by depressing the button to effect energization oi the sound producing device from the oscillator to the amplifier, a plurality oi! push-button switches disposed in series generally concentric with respect to the first said switch and operable collectively, singly or in a group to correspondingly change the periodicity oi the oscillations produced by the oscillator, a second sound producing device operable through the amplifier, and depressing movement of the first switch energizing the first sound producing device being adapted to deenergize the second sound producing device.

HOWARD J. FINDLEY. 

